28 research outputs found
First Steps in the Cross-Comparison of Solar Resource Spatial Products in Europe
International audienceYearly sum of global irradiation is compared from six spatial (map) databases: ESRA, PVGIS, Meteonorm, Satel-Light, HelioClim-2, and NASA SSE. This study does not identify the best database, but in a relative cross-comparison it points out to the areas of higher variability of outputs. Two maps are calculated to show an average of the yearly irradiation for horizontal surface together with the standard deviation that illustrates the combined effect of differences between the databases at the regional level. Differences at the local level are analysed on a set of 37 randomly selected points: global irradiation is calculated from subset of databases for southwards inclined (at 34°) and 2-axis tracking surfaces. Differences at the regional level indicate that within 90% of the study area the uncertainty of yearly global irradiation estimates (expressed by standard deviation) does not exceed 7% for horizontal surface, 8.3% for surface inclined at 34°, and 10% for 2-axis tracking surface. Higher differences in the outputs from the studied databases are found in complex climate conditions of mountains, along some coastal zones and in areas where solar radiation modelling cannot rely on sufficient density and quality of input dat
Solar Atlas for the Southern and Eastern Mediterranean
International audienceSouthern and eastern Mediterranean regions are prone to production of electricity by solar systems. The solar resource is the "fuel" of such systems and its availability is a key economic parameter in system design. Even though the southern and eastern Mediterranean region is served by several commercial data providers, in a public domain, so far only coarse resolution (100 km) data or data with limited temporal coverage is available. For more rapid development of policies and to attract the industrial interest in this region a more enhanced and easy to access free information is needed. The project will bring high resolution (1 km), long term coverage of at least 15 years data on the available solar resources for the region covering the countries Syria, Jordan, Israel, Lebanon, Egypt, Libya, Tunisia, Algeria, Morocco, Palestine National Authority, Mauretania and Turkey. The resource data will be derived from Earth Observation satellite data, based on published and transparent methodologies and the data will be validated with existing ground measurements in the region. The database will be provided by SOLEMI and Helioclim-3 (SoDa) sources - Global Horizontal Irradiation (GHI) and Direct Normal Irradiation (DNI). The data will be made available via a distributed information system which will ensure the ease of access to the data. The free access to the data will include historical, annual and monthly averages, and more detailed data products and services will remain the domain of commercial data providers. This paper will show the first prototype of the user interface for an easy web access to the solar radiation as well as ancillary geographical data. With the presentation of this paper we aim to encourage potential users to give us feedback on the further development
MESoR - Management and exploitation of solar resource knowledge
CD-ROMKnowledge of the solar resource is essential for the planning and operation of solar energy systems. A number of data bases giving information on solar resources have been developed over the past years. The result is a fragmentation of services each having each own mechanism of access and all are giving different results due to different methods, input data and base years. The project MESoR, co-funded by the European Commission, reduces the associated uncertainty by setting up standard benchmarking rules and measures for comparing the data bases, user guidance to the application of resource data and unifying access to various data bases
Responsive Operations for Key Services (ROKS): A Modular, Low SWaP Quantum Communications Payload
Quantum key distribution (QKD) is a theoretically proven future-proof secure encryption method that inherits its security from fundamental physical principles. With a proof-of-concept QKD payload having flown on the Micius satellite since 2016, efforts have intensified globally. Craft Prospect, working with a number of UK organisations, has been focused on miniaturising the technologies that enable QKD so that they may be used in smaller platforms including nanosatellites. The significant reduction of size, and therefore the cost of launching quantum communication technologies either on a dedicated platform or hosted as part of a larger optical communications will improve potential access to quantum encryption on a relatively quick timescale.
The Responsive Operations for Key Services (ROKS) mission seeks to be among the first to send a QKD payload on a CubeSat into low Earth orbit, demonstrating the capabilities of newly developed modular quantum technologies. The ROKS payload comprises a quantum source module that supplies photons randomly in any of four linear polarisation states fed from a quantum random number generator; an acquisition, pointing, and tracking system to fine-tune alignment of the quantum source beam with an optical ground station; an imager that will detect cloud cover autonomously; and an onboard computer that controls and monitors the other modules, which manages the payload and assures the overall performance and security of the system. Each of these modules have been developed with low Size, Weight and Power (SWaP) for CubeSats, but with interoperability in mind for other satellite form factors.
We present each of the listed components, together with the initial test results from our test bench and the performance of our protoflight models prior to initial integration with the 6U CubeSat platform systems. The completed ROKS payload will be ready for flight at the end of 2022, with various modular components already being baselined for flight and integrated into third party communication missions
Surface-Anchored Monomeric Agonist pMHCs Alone Trigger TCR with High Sensitivity
At the interface between T cell and antigen-presenting cell (APC), peptide antigen presented by MHC (pMHC) binds to the T cell receptor (TCR) and initiates signaling. The mechanism of TCR signal initiation, or triggering, remains unclear. An interesting aspect of this puzzle is that although soluble agonist pMHCs cannot trigger TCR even at high concentrations, the same ligands trigger TCR very efficiently on the surface of APCs. Here, using lipid bilayers or plastic-based artificial APCs with defined components, we identify the critical APC-associated factors that confer agonist pMHCs with such potency. We found that CD4+ T cells are triggered by very low numbers of monomeric agonist pMHCs anchored on fluid lipid bilayers or fixed plastic surfaces, in the absence of any other APC surface molecules. Importantly, on bilayers, plastic surfaces, or real APCs, endogenous pMHCs did not enhance TCR triggering. TCR triggering, however, critically depended upon the adhesiveness of the surface and an intact T cell actin cytoskeleton. Based on these observations, we propose the receptor deformation model of TCR triggering to explain the remarkable sensitivity and specificity of TCR triggering
Identifying Individual T Cell Receptors of Optimal Avidity for Tumor Antigens.
Cytotoxic T cells recognize, via their T cell receptors (TCRs), small antigenic peptides presented by the major histocompatibility complex (pMHC) on the surface of professional antigen-presenting cells and infected or malignant cells. The efficiency of T cell triggering critically depends on TCR binding to cognate pMHC, i.e., the TCR-pMHC structural avidity. The binding and kinetic attributes of this interaction are key parameters for protective T cell-mediated immunity, with stronger TCR-pMHC interactions conferring superior T cell activation and responsiveness than weaker ones. However, high-avidity TCRs are not always available, particularly among self/tumor antigen-specific T cells, most of which are eliminated by central and peripheral deletion mechanisms. Consequently, systematic assessment of T cell avidity can greatly help distinguishing protective from non-protective T cells. Here, we review novel strategies to assess TCR-pMHC interaction kinetics, enabling the identification of the functionally most-relevant T cells. We also discuss the significance of these technologies in determining which cells within a naturally occurring polyclonal tumor-specific T cell response would offer the best clinical benefit for use in adoptive therapies, with or without T cell engineering
Analysis of One-axis Tracking Strategies for PV Systems in Europe
We present a method for estimating the energy output from one-axis tracking non-concentrating PV systems and compare the yields from different configurations. The method is based on the use of solar radiation and temperature databases and models for the performance of PV modules under given geographic conditions. In the resulting maps of energy yield for Europe it is found that there are two different one-axis configurations that perform almost as well as a full two-axis sun-tracking system: one with a vertical axis and inclined modules, and the other with an inclined axis directed north-south and modules in the plane of the axis. When the inclination angles of the modules are optimized, these two configurations have an energy yield compared to an optimal fixed mounting that is approximately 30% higher in southern Europe, about 20-25% higher in central Europe, and up to 50% higher in northern Scandinavia. Compared to the two-axis tracking, the yields are only 1-4% lower, making such one-axis tracking systems very attractive in terms of performance relative to technical complexity and price.JRC.F.7-Renewable Energy (Ispra
Open Source Solar Radiation Tools for Environmental and Renewable Energy Applications
Solar energy is the main driver of natural processes on the Earth surface, and is used as an input parameter into many environmental models. Moreover, the importance of solar energy as a source of clean renewable energy for solar electricity and heating/cooling systems is growing worldwide. To improve underst anding of spatial and temporal variations of solar radiation, models integrated in or coupled with geographical information systems (GIS) were developed. The r.sun solar radiation model and other related programes were developed and implemented in the open-source GRASS GIS to deal with the complex chain of algorithms and input parameters needed in solar resource assessments. In this paper, we briefly describe r.sun and related algorithms from the point of view of methodology, input/output data and possible applications. We present application examples mainly in the field of photovoltaics for three different spatial scales (continental, regional and local). The results show that open source concept of the r.sun methodology allows flexible development of the extended models and purpose-driven applications.JRC.F.8-Renewable energies (Ispra
Optimal mounting strategy for single-axis tracking non-concentrating PV in Europe
We present a map-based method for estimating the yearly solar irradiation received by a PV modules mounted on a sun-tracker with a single axis of movement. The method finds the annual in-plane irradiation and calculates the optimum angle of inclination for a vertical-axis system with inclined modules or an inclined-axis system with the plane of the modules parallel to the axis of rotation. The approach is applied to the PVGIS climate database extending the European Subcontinent. Results indicate that optimised 1-axis tracking systems perform almost as well as a full 2-axis sun-tracking system. We also demonstrate that the use of such tracking systems is particularly advantageous at high latitudes (above 60° North), allowing tracking systems there to have the same yield as systems located in Central Europe.JRC.C.2-Energy Efficiency and Renewable
First Steps in the Cross-Comparison of Solar Resource Spatial Products in Europe
Yearly sum of global irradiation is compared from six spatial (map) databases: ESRA, PVGIS, Meteonorm, Satel-Light, HelioCliom-2, and NASA SSE. This study does not identify the best database, but in a relative cross-comparison it points out to the areas of higher variability of outputs. Two maps are calculated to show an average of the yearly irradiation for horizontal surface together with the standard deviation that illustrates the combined effect of differences between the databases at the regional level. Differences at the local level are analysed on a set of 37 randomly selected points: global irradiation is calculated from subset of databases for southwards inclined (at 34°) and 2-axis tracking surfaces. Differences at the regional level indicate that within 90% of the study area the uncertainty of yearly global irradiation estimates (expressed by standard deviation) does not exceed 7% for horizontal surface, 8.3% for surface inclined at 34°, and 10% for 2-axis tracking surface. Higher differences in the outputs from the studied databases are found in complex climate conditions of mountains, along some coastal zones and in areas where solar radiation modelling cannot rely on sufficient density and quality of input data.JRC.F.7-Renewables and Energy Efficienc